An attempt to decrease toxicity and preserve therapeutic effect, high-dose "pulse" methylprednisolone has been tried. Since oral dosage forms were employed, attempts were made to obtain an estimate of the fraction that enters the systemic circulation. Our results indicate that administration of 1 g methylprednisolone as capsules of its sodium succinate salt gave a plasma peak within 3.4 hours which averaged 6.2 g/ml. The half-life of drug absorption from capsules was approximately 45 minutes whereas the elimination half-life ranged from 2.5-4.7 hours. Early data from suspension dosage form shows comparable peak levels. The bioavailability of methylprednisolone from both dosage forms were approximately 60%. This adequate bioavailability makes it reasonable to administer high-dose methylprednisolone in more acceptable oral dosage form (compared to IV administration) for long term therapy.